Conclusions EV71 and CA16 were highly diverse in the nucleotide sequences of vp1s and vp4s. The severity of illness of EV71 infected was not associated with the sequence variation of vp1s or vp4s. The sera positive rates of VP1 and VP4 of EV71 were lower than that of CA16, suggesting less exposure rate to EV71 than CA16 in Beijing population. The detection of serum antibodies by Western blot using VP1s and VP4s as antigens indicated that the immunological reaction to VP1 and VP4 of both EV71 and CA16 was different. IgM against VP1 but not VP4 was

generated in children after acute infections, which needs to be clarified further. Methods Clinical specimens and isolation of viruses Throat swabs and vesicle fluids were collected from infants and children with clinical diagnosis of HFMD or suspected

Pevonedistat cell line EV infection who visited the Affiliated Children’s Hospital to Capital Institute of Paediatrics during the HFMD seasons TGFbeta inhibitor of year 2007 to 2009. The specimens were inoculated in Vero cells after being delivered to the Laboratory of Virology, and CPE were observed by microscopy everyday. When the CPE reached ++++, the isolates were harvested and stored at-80°C until use. Serum specimens Serum specimens for the detection of IgM antibodies against the expressed VP1s and VP4s were collected from infants and children with acute EV infection, click here including 14 from children with acute EV71 infection and 12 from children with acute CA16 infection identified by RT-PCR, virus isolation from throat swabs and vesicle fluids, and immnofluorescence staining of IgM against

EV71 or CA16 in sera (data not shown). Another batch of 189 sera were collected for the detection of IgG antibodies against the expressed proteins, including 141 from adults for regular health check up and 48 children without acute EV infections. The study was performed according to the Declaration of Helsinki II and approved by Ethics Committee of Capital Institute of Paediatrics and written informed consent was obtained from Sodium butyrate all patients or from their caretakers. Identification of EV71 and CA16 from clinical specimens and isolated viruses by RT-PCR RNAs were extracted from clinical specimens and isolated virus strains using Trizol (Invitrogen, USA) following the instructions provided by manufacture. RT-PCR was carried out to identify EV71 and CA16 in the specimens and virus isolates. Viral cDNAs were generated using random primer (Invitrogen, USA) and M-MLV (Invitrogen, USA) by reverse transcription. EV consensus primers, EV71 and CA16 specific primers were synthesized according to Perara D’s [33] and Singh S’ [35], and used to detect EV71 and CA16 by PCR as described by our group previously [29]. The PCR products were analyzed by electrophoresis in a 2% agarose (GibcoBRL, US) gel and visualized by staining the gels with ethedium bromide.